Does anyone know the breaking strengths for Mastery Saltwater 12 weight fly lines or the other 12 Tarpon and offshore lines?

A friend just got back from his Christmas Island trip. He said he sat next to a guy on the plane out. The angler told my friend he uses fly lines designed for Marlin and Sailfish and said his have a 75 pound test core (My friend didn't remember the manufacturer's name). With the heavy core on the fly line, the guy said he used 65 lbs. braided line for backing (gel-spun line) and then straight # 60 fluorocarbon with an #80 shock tippet as leader. This way the leader theoretically still should break before the backing and he can crank down on the drag to get some semblance of control on a big Trevally. He said this was the best way to catch Trevally, especially large ones. I know there are some offshore line that have a #55 core. I am quite interested to see if there are any other fly lines with heavier core strengths.

I usually build in a 30 lbs. section in the leader to try and protect the fly line. However, on my trip to Christmas Island in January, several of my guides recommended leaders of straight 60 fluorocarbon to try and controll larger Trevally. This didn't make too much sense since my backing was only #30 dacron.

Maybe a heavier core fly line may be a way for fighting a number of large inshore and offshore/bluewater species.

You might want to look at the Rio Leviathan lines - I beleive they all have a core strength of 75# or better. They are great casting lines, btw. The setup your friend described is almost identical to what many bluefin anglers use, including the straight shot of heavy floro for a 'leader'. I have not broken a fly line but have toasted a couple of Leviathans while fighting fish, separating the core from the coating. The same setup is very effective for large wreck fish where you need to haul them away from structure without surrenduring any backing. A 12-weight is minimum firepower for this tactic IMHO. I would think the tippet is almost always going to snap before the line due to abrasion, the knot at the fly, and the generous amount of stretch in most mono-core fly lines.

My usual warning when attempting this type of setup: Fly fishing is different than other types of fishing due to the amount slack line involved. When that slack line is on the floor of the boat it can easily get wrapped around a leg, arm, wrist, etc. when a hot fish takes off. When that happens when we're bonefishing, etc. (and anyone who's done much bonefishing will admit it's happened to him/her) you just end up breaking the fly off at the tippet. When it happens in a bluewater environment with the weakest link being 65# you're going overboard in a heartbeat. If it's a tuna or some other fish that tends to sound, you could be in a heap of trouble. No one actually believes it will happen to him, but it can and does happen. That's one of the principle reasons the IGFA rules allow nothing heavier than 10kg (22#) for the weakest link in the leader. Think about it.

Intersting points. I have not used 60# but would not worry too much about 45#. Even with the most carefully tied knot, your break strength is going to be much less than than the rating. Worth taking into account the strengh of all connections including the bimini in the braid and conneciton from fly line to leader. I have had the line wrap around my hand or rod butt or get stuck underfoot on a tuna run. The tippet has always broken rather easisly. A friend of mine got wrapped around his watch a few years ago and it didn't even break the watch strap. 45# will snap if you overdo it on the drag and and the fish changes direction with a lot of backing out, creating a bow. What I would be very careful of is the braided backing leaving your reel at light speed. If you caught a finger in there, you could get severly injured. I should also mention that I almost always use a Pleskunas VLMD which virtually eliminates tangling when clearing line.

I heard some folks use Diawa Saltiga line as backing since it is somewhat more user friendy that some of the gel-spun lines. I think the folk at Hatch fly reels told me they used Saltiga as backing. Their catalog lists the capacities for their larger reels using Diawa Saltiga 55# Boat Braid. They list the line at .014"/.36 mm diameter. Has anyone heard of comparisons between Saltiga braid and other small diameter heavy test lines used as backing?

A Pleskunas VLMD is a tub (Vertical Line Management Device.) It is designed to sit on the floor of the boat and the line is stripped into it. Often, when billfishing we've used 5 gallon buckets for much the same purpose. While using one does minimize the risk of getting line around you leg, it doesn't do much at all about line around your wrist or finger. I'll admit that 45# is better than 60# or more, but to say that there's no risk, or even minimal risk, is just not accurate. I'm aware of a celebrity flyfishermen (who's repeatly asked me to not mention his name when I deal with this issue) who was taken over the side of a boat with 30# class tippet while fishing for sailfish. If you try to break 30# or 45# mono or FC you'll find out just how strong it is. If you tie decent knots, you won't diminish the breaking strength by anything more than 10%, and if you choose the right knots, and tie them well, it'll be less than that. Look, you can do whatever you want, but at least you've been warned. Too many men think Indiana Jones is their brother and that things like this will never happen to them, or they'll figure something out in an instant if it does.

I've never heard of a fly line breaking before the tippet, leader, or a knot. So what does the fly line strength really matter?

The only fly line I've ever had that was shortened was because somehow I put a knot in a 4 wt line I have without realizing it about 15' from the tip end. I still can't figure out how that happened, but by the time I found it, it was so badly knotted I had to cut the fly line off at that point. It's just about the most puzzling thing I've ever seen in 25+ years of flyfishing and hundreds of thousands of casts. Other than that, every fly line I've ever owned has stayed whole, other than one that found a propeller.

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Scott

I've never heard of a fly line breaking before the tippet, leader, or a knot. So what does the fly line strength really matter?

It matters when pursuing large gamefish that have a real chance of breaking the typical fly line core. If that core is the weak link in your setup, then your line will break. I speak from first hand experience on this, both for myself and others on the boat....